This scandal mainly affected women, who were entitled to have their pensions increased by the DWP without asking.
Those affected reached state pension age before April 2016. They include wives entitled to a pension worth 60 per cent of their husband’s basic rate, and also divorcees and widows who could claim as much as 100 per cent.
Other people who were left out included pensioners, who after turning 80 should have received at least 60 percent of the basic state retirement pension.
The basic rate state pension pays £137.60 a week, so someone on a 60 per cent rate should receive around £82.45.
The 60 percent rate is available to wives from the time their husband reaches state pension age.
Not taken into consideration: Wives may not have received vital forms when they were due to file their claim. (file photo)
However, a March 2008 rule change required that the Department for Work and Pensions automatically pay the higher pension.
Women who were not yet at state pension age had to be able to receive the additional income.
Uninformed pensioners can increase their retirement income, but they cannot get all the money that was lost.
The DWP states that those whose husbands became eligible to their pension on March 17, 2008 or later, don’t need to act and they will be contacted.
To find out if you’ve been short-changed, go to lcp.uk.com/is-your-state-pension-being-underpaid.
You can contact the Pension Service at 0800 731 0469 if you feel you’re missing something or send an email to The Pension Service Post Handling Site 1, Wolverhampton WV981AF.